Interfacial reaction between Ag and NdBa₂Cu₃O_{7- δ} superconductor prepared by low-temperature process

The interfacial reaction between Ag and NdBa₂Cu₃O_7-δ (Nd123) was examined from the viewpoint of low-temperature processing of superconducting materials. The incongruent melting temperature of an Nd123 sample was measured to be as low as 960°C in N₂. Addition of 10 mass% of Ag to Nd123 decreased further the incongruent melting temperature of Nd123 to 920°C. By a model experiment using an Ag pellet embedded in Nd123, it was revealed that an Ag-dissolved (Ba,Cu)-rich phase was formed near the interface with Ag. Based upon these results, Ag-added Nd123 ceramic samples were prepared by the partial melting process at temperatures below the melting point of Ag, 960°C. Superconducting properties of the ceramic samples were improved by the addition of Ag.